Dial-out link selection via static route redistribution

ABSTRACT

Dial-out route service is forwarded by a gateway to reduce congestion in a data communication network. The first gateway determines availability of it ports to provide dial-out service for a dial-out route. If the first gateway is unable to provide dial-out service to the dial-out route, the first gateway transfers information corresponding to the dial-out route to a second gateway. The second gateway may access a central database storing static routes corresponding to the transferred dial-out route information. The second gateway advertises the transferred dial-out route. The dial-out route may be terminated based on one or more termination parameters. Forwarding dial-out route service may be used to dynamically scale dial-out service provided by a gateway.

RELATED APPLICATION(S)

This application is a continuation of U.S. application Ser. No.09/479,527, filed Jan. 7, 2000 now U.S. Pat. No. 6,738,824, which is acontinuation of U.S. patent application Ser. No. 09/281,591, entitled“Method and Apparatus Providing Dial On Demand Scaling,” by Dana Blair,filed Mar. 30, 1999. The entire teachings of the above applications areincorporated herein by reference.

BACKGROUND OF THE INVENTION

Users of network devices connected to networks, such as the Internet,access remote devices, such as web servers, to provide the users withinformation. Between the user's network device and the remote devicesare various networks, PSTNs (Public Switched Telephone Network),routers, subnet devices, etc. One device that allows users to connect toa PSTN is a device referred to as a gateway (GW), or Network AccessServer (NAS), which is typically a router providing various networkcommunication protocols, such as ISDN (Integrated Services DigitalNetwork), POTS (Plain Old Telephone System), and other modem andnon-modem communication protocols. At various locations around a networkare nodes, which can transmit and/or receive communications to/fromother nodes on the network. Nodes include devices such as computers,routers, telephones, cell-phones, fax machines, hand-held networkdevices, etc., and/or software, residing on any of the aforementioneddevices, and multiple software modules, in cases where software operatesin parallel on a single device.

A typical GW has a fixed number of ports, one hundred, for instance.Each port allows both dial-in and dial-out service. Once a port isallocated for dial-in service, the port remains so until the connectionfrom a node to the GW (or, more precisely, from a first node to a secondnode via the GW) is released. The same is true for a port allocated fordial-out service, where the port remains allocated for dial-out serviceuntil the connection from the GW to a remote network node is released.For example, a port is allocated for dial-in service when a node, suchas a web browser, dials into the GW to access a remote web server towhich the GW provides service. A GW port is allocated for dial-outservice when connection is made from the GW to a node, such as a webserver, to which the GW provides access, possibly through other nodes,such as routers.

Dial-in service is a relatively mature technology. Dial-in servicetechnology presently allows connections to non-allocated ports to beestablished automatically. An example of dial-in service technology is aso-called “hunt” algorithm, which is commonly used in automated1-800-telephone systems. When a call is received at a 1-800-servicecenter, a non-allocated port is automatically allocated to the incomingcall. This automated connectivity technology allows service providers(e.g., Internet service providers (ISPs)) to over-subscribe the numberof users subscribed to access the Internet through the ISP's GW.Over-subscription of dial-in service is possible because of the matureautomated connectivity technology and an assumption that not all of thesubscribed users will attempt to connect through the GW at the sametime. ISPs may over-subscribe dial-in service customers to GW ports by aratio of 5, 10, 15, or more, to 1. In the event that all GW ports arebeing used, further dial-in customers receive a “connection failure”message, though this case has become rare due to the above-describeddial-in service technology.

Dial-out service is not as mature a technology as dial-in service. Indial-out service, a GW has a static route table of nodes that arereachable by the GW. But, because the GW has a limited number of ports,GWs typically assign/reserve ports for dial-out service to specificroutes or nodes. In that way, when nodes dial-in and request dial-outservice to other nodes, the GW has ports available for the dial-outservice.

If a PSTN network is coupled to fifty remote subnets, for example, theGW's static route table includes information to access each of the fiftyremote subnets. However, because the GW has a limited number of ports,as discussed above, the ISP must make some decisions about GWconfiguration in order to prevent customers attempting to use dial-outservice from receiving a “connection failure/remote server busy” orother such message. To this end, ISPs typically have one GW configuredto provide only dial-in service and several (more than necessary) GWs toprovide dial-out service.

SUMMARY OF THE INVENTION

The problem is that, presently, GWs are not inherently flexible in theirscalability and fail-safe operation. Each GW has its own static routetable, but is unable to share dial-out route entries in the static routetable with other GWs to dynamically scale the number of ports availableto support its static route table entries. Without such dynamicscalability, ISPs must have an over-abundance of GWs to support expectedpeak usage, which is increasing at a rapid pace with the emergence ofweb-based, hand-held devices, including wireless phones, and one-to-manymedia distributions by information providers to end users. Eachhand-held device requires a dial-out service port, and each informationprovider requires access to each media distribution destination via adial-out service port. GWs are expensive pieces of equipment, so it isin the ISP's best interest to have GWs be flexible such that the numberof GWs dedicated to dial-out service is minimized, but optimized.

The present invention includes forwarding dial-out service provided by agateway to reduce congestion in a data communication network. Fornetwork nodes that access a first gateway for dial-out service, thefirst gateway determines availability of ports providing dial-outservice. Information corresponding to a dial-out route that isdetermined by the first gateway to be causing congestion, or will becausing congestion in the future, is transferred from the first gatewayto a second gateway. Transferring the dial-out route information allowsthe gateways to forward dial-out service. Static route transfers amonggateways may also result in dynamically, and automatically, scalingdial-out service provided by the first gateway.

The second gateway may access a central database storing static routescorresponding to the transferred dial-out route information. The centraldatabase is typically stored on a server providing security services.These security services may include access, authentication, andauthorization.

The first gateway may issue a request to the second gateway prior totransferring the dial-out route. The first gateway determines whetherthe second gateway wishes to accept the dial-out route. The firstgateway may also transfer a respective priority level parameterassociated with the dial-out route. Upon accepting the dial-out route,the second gateway advertises the transferred dial-out route and arespective priority level to effectuate the dial-out route transfer. Inaddition to transferring an optional respective priority levelparameter, the first gateway may also transfer a termination parameterto limit dial-out route transfer time. The termination parameters mayinclude a time-to-live parameter, delete-after-complete parameter, ordelete-upon-reboot parameter.

In an alternate embodiment, a network node, which is typically anothergateway or central gateway monitor, determines a state of dial-out routeservice of the first gateway. The network node retrieves at least onedial-out route reachable from the first gateway from a central databasestoring static routes. The retrieved dial-out route is assigned toanother gateway to provide service to the dial-out route. The nodecontinually re-assesses the state of dial-out route service of the firstgateway to restore the retrieved dial-out route. This embodimentmonitors gateways to ensure they are functioning properly and providesuninterrupted dial-out service to routes supported by the first gatewayuntil such time as the first gateway can again provide dial-out routeservice to the retrieved dial-out route.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

FIG. 1 is a block diagram of an example network in which the presentinvention is deployed;

FIG. 2 is a flow diagram of an embodiment of a process of the presentinvention operating in the example network of FIG. 1;

FIG. 3 is a block diagram of multiple gateways interconnected in amanner supporting the process of FIG. 2; and

FIG. 4 is a block diagram of multiple gateways interconnected in amanner supporting an alternate embodiment of the process of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

A description of preferred embodiments of the invention follows.

FIG. 1 is a block diagram of an example network in which the presentinvention may be deployed. In the network 100, a PSTN 103 is coupled tothe Internet 142 by a pair of gateways (GWs) 105 a, 105 b. The GWs 105have access to an AAA (access, authentication, and authorization server)145 via the Internet 142. The GWs 105 provide dial-in and dial-outservice for the nodes coupled to the Internet 142 and PSTN 103. The GWs105 provide ISDN, POTS, modem, etc. communication protocols to couplethe nodes, which operate under the different communication protocols.Network nodes include computers, VoIP phones, hand-held devices (e.g.palm-top computers), network appliances, fax machines, or softwareperforming communication on a network device. A network node sometimesloosely refers to a subnet, PSTN, or other set of network devices thatcan be referenced as a single entity.

The PSTN 103 is coupled either electrically (over wire or fiber optic)or wirelessly (via RF or optically) with network nodes. Network nodescoupled to the PSTN 103 include router 121, PSTN 136, and the Internet142 (via the gateways 105). There are also several nodes connecteddirectly to the PSTN 103, including: GW 109, GW 112, workstation 115,and workstation 118.

The subnet 124 is an example of a typical corporate networkconfiguration. The subnet 124 comprises an ethernet 125 on which nodes,such as workstations 127, 130 and a wireless telephone 133 operate. Thesubnet 124 is coupled to the PSTN 103 via the router 121, which mayperform network address translation or other firewall-forms of security.

The PSTN 136 has a single workstation 139 coupled to it. The workstation139 accesses the PSTN 136, and is accessed from the PSTN 136, throughthe workstation's phone number 140. The connection coupling the PSTNs136, 103 is transparent to the gateways 105 and other network nodes.

The Internet 142 has several nodes coupled to it. The nodes include anAAA 145, workstation 148, and wireless IP phone 151. Of course, thereare many other forms of nodes and networks (not shown) coupled to theInternet 142. The nodes shown here are merely exemplary of three formsof nodes to provide some structure for discussion.

During typical GW bootup sequencing, the GWs 105 get their respectivestatic route table information from the AAA 145. Note that the AAA 145is a server that performs access, authentication, and authorizationcontrol, typically for nodes requesting dial-in access to the Internet.In the past, the AAA 145 only had dial-in reachability information,passwords, etc. (See co-pending application Ser. No. 09/281,591previously referenced). However, for use in the present invention, theAAA 145 also provides a dial-out reachability database 146, which isstored in working memory of the AAA 145. An example of a record in thereachability database 146 is the following:

IP route 1.1.1.0 255.255.255.0 1.1.1.1 name remote_router, where thefirst two fields refer to a subnet, and the next fields refer to anaddress of a remote node, here a router.

In order to manage over-subscription for dial-out service, the GWs 105,in one embodiment, have the following arrangement. GW1 is a master GWfor dial-out routes (i.e., static routes) to network nodes for which GW1provides dial-out service. GW2 is a master GW for dial-out routes tonetwork nodes for which GW2 provides dial-out service. The dial-outroutes for which each GW is a master corresponds to the dial-out routesin each respective GW's static route table. In one embodiment of thepresent invention, the AAA 145 has a master copy of all entries in eachGW's routing table for each GW that has access to the AAA 145 or iswithin the AAA 145 service zone, in this case, the Internet 142.

FIG. 2 is a flow diagram of an embodiment of the present inventionrelating to a system in which a first gateway (GW1) determines it, orone of the dial-out routes it services, is in a state of congestion. Astate of congestion means that (i) all ports in the GW are busy, (ii)the ports that have been allocated to provide dial-out service to thedial-out routes are busy, or (iii) the nodes to which the GW attempts toconnect are busy. If GW1 determines itself to be in a state ofcongestion, it seeks support for the congested dial-out route(s) fromanother gateway (see application Ser. No. 09/281,591, incorporated byreference herein). In the description provided, it is assumed that theprocess 200 relates to the example network 100 (FIG. 1), unlessotherwise specified.

The process 200 begins when W1 sends a packet to W2, represented by step205. The packet from W1 arrives at GW1 in step 210. In query 215, GW1determines whether it, or the dial-out route it provides as service toconnect to W2, is in a state of congestion.

In step 215, if GW1 determines that it is not in a state of congestion,then, in step 220, GW1 simply provides dial-out service, through one ofits ports to the remote router 121, to W2. The route includes connectionthrough the PSTN 103. The process is complete in step 275.

If, however, in step 215, GW1 determines itself to be in a state ofcongestion, then processing continues in step 225. In step 225, GW1selects an alternate GW to provide dial-out service to W2, via therespective dial-out route. In the example network 100, GW1 has only GW2as an alternate GW. However, there may be three or more GWs locatedtogether, or distributed about the Internet 142, that can providesupport as alternate GWs.

After selection of an alternate GW in the step 225, in step 230, GW1sends an assignment packet to the selected alternate GW. The assignmentpacket includes parameters for the route to W2. In step 240, thealternate GW downloads route(s) to W2 from the AAA 145, based on asubset of the parameters received from GW1 for the route to W2. Notethat steps 230 and 240 may be combined if an embodiment is used whereGW1 simply transfers the entire dial-out route to the alternate GW,rather than transferring only parameters. To transfer the static routesdirectly to the alternate GW, GW1 may employ a dynamic routing protocol,such as OSPF (open shortest-path first).

In step 250, the alternate GW advertises the transferred dial-out routeto inform other network nodes, including other GWs, that it is presentlyproviding service to the advertised route. Typically, advertisementsinclude a priority level to avoid network contention. For example, ifGW1 and GW2 advertise service to the same dial-out route, such asservice to W2, then if GW1 advertises the route with a priority level of‘1’ and GW2 advertises the route with a priority level of ‘2’, then, ina protocol where higher values indicate higher priority, GW2 will be theGW to which the other nodes send packets for dial-out service to W2.Advertising allows packets to be rerouted from one GW to another withoutaltering the contents of the packets, without depending on specialbehavior of the source of the IP packets, and without relying on dynamicrouting between the nodes and the GWs.

In step 260, communication between W1 and W2 occurs through thealternate GW, GW2. This communication continues through the alternate GWuntil the communication is complete. The first packets (and subsequentpackets), issued to GW1 by W1 prior to the dial-out route transfer fromGW1 to GW2, are included in the communications in step 260 because thesepackets are stored in GW1 while GW1 is in a state of congestion. WhenGW2 advertises the route, GW1 sends the stored packets to GW2 forservice of those packets to W2.

In step 265, the alternate GW deletes the dial-out route to W2 from itsstatic route table. In an alternate embodiment, the dial-out route maybe returned from GW2 to GW1, or passed to another GW, prior tocommunication completion between W1 and W2. In yet another embodiment,the transferred route is terminated after a reboot of either of the GWsinvolved in servicing the dial-out route to W2.

In step 270, GW1 restores the retransferred dial-out route from GW2 andadvertises the restored route and a respective priority level. Since GW2no longer advertises the dial-out route to W2, then all nodes updatetheir respective static route tables with information contained in GW1'sadvertisements, accordingly. Note that GWs typically advertise theirstatic route table information to other nodes on a regular basis, whichinforms the other nodes of the current state of each GW's static routetable. The process 200 is finished in step 275.

The process 200 also provides for continued checking by the alternate GWof its own state of congestion to ensure that it has not entered a stateof congestion before communication between W1 and W2 begins in step 260.The alternate GW's first state of congestion check is done in step 235,after GW1 sends the assignment packet to the alternate GW. If thealternate GW has entered a state of congestion between steps 225 and theend of step 230, then the alternate GW sends GW1 a message indicatingthat GW1 should select a different alternate GW. If the alternate GW isnot in a state of congestion, then processing continues in step 240.

In step 245, the alternate GW does a second check to determine whetherit has entered a state of congestion during the process 200. This secondstate of congestion check ensures the alternate GW has not entered astate of congestion while the alternate GW downloads the routes from theAAA 145, in an embodiment supporting a central. static route database.If the alternate GW determined itself to be in a state of congestion,then, in step 247, the alternate GW deletes the transferred route fromits static route table. Then, GW1 attempts to select another alternateGW in step 225. If, in step 245, the alternate GW is determined to benot in a state of congestion with respect to dial-out service to W2,then processing continues in step 250.

In step 255, a third test regarding alternate GW congestion is done instep 255. If the alternate GW is determined to be congested in step 255,then, in step 247, the dial-out route is deleted from the alternate GW'sstatic route table. In step 225, GW1 again attempts to select anotheralternate GW for the subject dial-out route. In step 255, if thealternate GW is determined to be not in a state of congestion withrespect to the dial-out route service to W2, then processing continuesin step 260, as described above. Of course, if dial-out service to W2cannot be provided by GW1 or GW2, or any other alternate GW, then W1receives a “service busy” message.

In an alternate embodiment of the process 200, rather than waiting for anode to request dial-out service to another node, each GW maycontinually check itself to determine whether its static routes are in astate of congestion and whether support from an alternate GW should besought at that time, prior to receiving a dial-out service request fromanother node. In such an embodiment, step 215 becomes the starting pointfor the process 200, and various minor modifications to the process 200are employed and may be understood and determined by inspection.

The process 200 may also be used to understand a process occurringinside an alternate GW. The alternate GW receives a dial-out routetransfer request from GW1. The alternate GW determines whether to acceptGW1's dial-out route transfer request. And, if the alternate GW acceptsto provide service to the subject dial-out route, the alternate GWadvertises the transferred route and a respective priority level. In oneembodiment, the alternate GW accesses the reachability database 146 inthe AAA 145 to retrieve complete routing information.

The process of FIG. 2, with little modification, may also be understoodto be an embodiment in which a GW or other network node determines thestate of congestion of a first GW, GW1 (FIG. 1). For example, GW1 may befully or partially off-line for any number of reasons, including poweroutage, system crash, congestion, or no links available. Another GW thatis configured to monitor GW1 assesses the state of congestion of GW1 andseeks an alternate GW, optionally including itself, to provide dial-outservice to routes unable to be serviced by GW1 due to GW1's state ofcongestion. In this embodiment, steps 215 through 275 are performed in aGW other than GW1 to accomplish the static route forwarding task. Since,in a state of congestion, GW1's static route table may be inaccessibleby another GW, a duplicate GW1 static route table is stored on a server,such as AAA 145, accessible by each potential alternate GW so that GW1'sstatic routes may be forwarded.

FIG. 3 is a block diagram of an embodiment of a system in which GW1seeks an alternate GW from among a group of GWs 105 b, 105 c, . . . ,105 n. Each of the GWs 105 has access to the AAA 145. The GWs need notbe local to one another (i.e., stacked on the same shelf or even in thesame room); the GWs 105 may be coupled to each other across variouslinks and nodes on, for example, the Internet 142 (FIG. 1). Afterdial-out routes are transferred from one GW to an alternate GW, routingmetrics (standard in network communication protocols) associated witheach of the dial-out routes are updated by the GWs, accordingly.Updating routing metrics typically includes a GW advertising the updatedrouting metrics along with the static route and its priority level. Eachof the GWs may have access to a single PSTN 103, multiple PSTNs (notshown), or entirely different PSTNs. However, a static route may only betransferred between or among GWs that have access to the destination ofthe static route via one or more network links, nodes, etc.

FIG. 4 is a block diagram of an alternate embodiment of a systememploying the present invention. In this case, the Internet 142 has amaster GW, GW1 105 a, that is configured to be in a constant state ofcongestion with respect to dial-out routes. The Internet 142 may alsoinclude the AAA 145 and is connected to the PSTN 103 through one or moreGWs, namely GW2 105 b, GW3 105 c, . . . , GWn 105 n.

Because, in this embodiment, GW1 is configured in a constant state ofcongestion, it continually determines alternate GWs for each of thedial-out routes in its static route table. The prospective alternate GWsinclude GW2, GW3, ., GWn. This arrangement tends to dynamically movevarious dial-out routes among the alternate GWs and dynamically scaledial-out route service to remote network nodes.

Similar to the embodiment of FIG. 1, in this embodiment, the master GWmay transfer a set of parameters to the alternate GWs, which requiresthe alternate GWs to access the corresponding full dial-out route fromthe reachability database 146 in the AAA 145. In an alternateembodiment, the master GW transfers the entire dial-out route to thealternate GWs, in which case, the master GW consolidates certainaspects/functions provided by the AAA 145, which may include access,authentication, and/or authorization services.

In the embodiment depicted in FIG. 4, each of the alternate GWs 105b-105 n may also be a master for other static routes. Another embodimentmay include a second master that has access to each of the alternate GWsshown, and also has access to the AAA 145. Because the present inventionis dynamic, it encompasses the possibility of having a wide variety ofembodiments of master and alternate GWs to provide dial-out service.

The method of the present invention can be implemented by a processor inthe GW that executes computer instructions which are stored on acomputer readable medium, such as a ROM, CD ROM, hard disk, or otherform of computer storage device While this invention has beenparticularly shown and described with references to preferredembodiments thereof, it will be understood by those skilled in the artthat various changes in form and details may be made therein withoutdeparting from the scope of the invention encompassed by the appendedclaims.

1. A method for scaling dial-out services provided by a gateway in adata communications network to reduce congestion in the datacommunications network, the method comprising: by a first gateway,advertising dial-out services for at least one dial-out route to thenetwork via a routing protocol; determining an availability of ports inthe first gateway to provide the dial-out services for network nodesthat access the first gateway for the dial-out services; transferringfrom the first gateway to a second gateway dial-out route informationcorresponding to at least one dial-out route for updating a routingtable in the second gateway; and by the first gateway, discontinuingadvertising the dial-out services for the at least one dial-out route toeffectuate transfer of dial-out services of the at least one dial-outroute.
 2. The method according to claim 1 further including accessing acentral database storing static routes corresponding to the transferreddial-out route information.
 3. The method according to claim 2 whereinthe central database is stored on a server providing security services.4. The method according to claim 1, further including: issuing a requestto the second gateway to transfer the at least one dial-out routecorresponding to the dial-out route information prior to transferringthe dial-out route.
 5. The method according to claim 4, furtherincluding identifying whether the second gateway chooses to accept theat least one dial-out route.
 6. The method according to claim 1, whereintransferring the dial-out route information includes transferring arespective priority level parameter associated with the at least onedial-out route.
 7. The method according to claim 6 further includingadvertising the transferred at least one dial-out route and respectivepriority levels by the second gateway to effectuate dial-out serviceusing the at least one dial-out route by the network nodes.
 8. Themethod according to claim 1 wherein transferring the dial-out routeinformation further includes transferring at least one transfertermination parameter to limit the length of time dial-out services ofthe at least one dial-out route is available to the network nodes by thesecond gateway.
 9. The method according to claim 8 wherein the at leastone transfer termination parameter includes at least one of thefollowing parameters: time-to-live, delete -after-complete, ordelete-upon-reboot.
 10. In a first gateway being used to expand dial-outservices in a data communications network, a method for scaling dial-outservices provided by the first gateway to reduce congestion in the datacommunications network, the method comprising: transmitting a dial-outroute transfer request, including dial-out route information, to asecond gateway; updating a routing table in response to receiving noticefrom the second gateway of a decision to accept the dial-out routetransfer request; transferring the dial-out route to the second gateway;and discontinuing advertising of dial-out services for the dial-outroute to the communications network using a routing protocol toeffectuate the dial-out route transfer request to expand dial-outservices in the data communications network.
 11. The method according toclaim 10 further including deallocating the dial-out route from arespective gateway port.
 12. The method according to claim 10 furtherincluding assigning a lower priority to the dial-out route than thedial-out route has in the second gateway.
 13. The method according toclaim 10 further including: accessing a database, having records ofrouting information for network nodes reachable by the network, for arecord corresponding to the transferred dial-out route.
 14. The methodaccording claim 13 wherein accessing the database includes communicatingwith a server providing security services.
 15. The method according toclaim 14 wherein the server is an access, authentication, andauthorization server.
 16. The method according to claim 10 furtherincluding transmitting a static route transfer duration parameter. 17.The method according to claim 10 further including forwarding at leastone termination parameter to the second gateway to cause the secondgateway to terminate the transferred dial-out route according to atleast one termination parameter.
 18. The method according to claim 17wherein the termination parameter includes at least one parameter:time-to-live, delete-after-complete, or delete-upon -reboot.
 19. Asystem for scaling dial-out services provided by a gateway in a datacommunications network to reduce congestion in the data communicationsnetwork, the system comprising: a first gateway advertising dial-outservices for at least one dial -out route to the data communicationsnetwork via a routing protocol; a routing table in the first gatewayincluding the at least one dial-out route, the first gatewaytransferring to a second gateway at least one parameter related to astatic dial-out route in the routing table, the first gatewaydiscontinuing advertising the dial-out services corresponding to thestatic dial-out route associated with the at least one transferredparameter to reduce congestion in the data communications network. 20.The system according to claim 19 wherein the first gateway accesses aserver providing a reachability database, the reachability databaseincluding static routes accessible by the first and second gateways. 21.The system according to claim 20 wherein the first gateway is adapted toaccess the server via security services employed by the server.
 22. Thesystem according to claim 21 wherein the server is an access,authentication, and authorization server.
 23. The system according toclaim 20 wherein the first gateway retrieves dial-out routes from thereachability database.
 24. The system according to claim 19 wherein thefirst gateway transfers the static route parameters in response todetermining a reduced number of gateway ports being able to providedial-out route services for a static route corresponding to the at leastone static route parameters.
 25. The system according to claim 19wherein the first gateway advertises non-transferred dial-out routes onthe data communications network as a function of increased capacityresulting from transferring the dial-out services for the respectivestatic route.
 26. The system according to claim 25 wherein the firstgateway includes a dial-out route priority parameter in the at least onetransferred parameter that the second gateway includes in advertisementsabout the static route dial-out service to other network nodes.
 27. Thesystem according to claim 26 wherein the first gateway calculates thestatic route priority parameter.
 28. The system according to claim 26wherein the first gateway provides information to the second gatewaythat allows the second gateway to calculate the static route priorityparameter.
 29. The system according to claim 19 wherein a serverincluding a reachability database accessible by the first and secondgateways includes the static route priority parameter in the database.30. The system according to claim 19 wherein the first gatewayterminates dial-out service of the transferred static route by thesecond gateway.
 31. The system according to claim 30 wherein the firstgateway transfers a termination parameter to the second gateway, thetermination parameter causing the second gateway to terminate thetransferred static route.
 32. An apparatus for scaling dial-out servicesprovided by a gateway in a data communications network to reducecongestion in the data communications network, the apparatus comprising:means for transferring dial-out routes from a first gateway to a secondgateway; means for reducing priority of the transferred dial-out routein the first gateway below the priority of the transferred dial-outroute in the second gateway; means for updating a routing table in thefirst gateway; and means for discontinuing advertising by the firstgateway of the dial-out route via a routing protocol to the datacommunications network as a function of the priority level of the atleast one dial-out route.
 33. The apparatus according to claim 32wherein said means for advertising the dial-out route informs reachablenetwork nodes of respective gateway routes and corresponding gatewayroute priorities to reduce data flow congestion in the datacommunications network.
 34. The apparatus according to claim 32 whereinsaid means for updating a routing table disables the dial-out route frombeing accessed via the first gateway by network nodes in the datacommunications network.
 35. The apparatus according to claim 32 whereinsaid means for transferring the dial-out route includes means fortransferring a terminating parameter that causes the transferreddial-out route to terminate in the second gateway according to apredetermined condition.
 36. A method for dynamically providing dial-outservice for a network node by a gateway, the method comprising:determining a state of dial-out services in a first gateway; retrievingat least one dial-out route reachable from the first gateway from acentral database storing dial-out routes for the first gateway; causinga second gateway to update its routing table with the retrieved dial-outroute to provide dial-out services to the dial-out route; anddiscontinuing advertising of the dial-out route via a routing protocolby the first gateway to allow advertising by the second gateway via therouting protocol to cause network nodes to access the second gateway fordial-out services of the dial-out route.
 37. The method according toclaim 36 further including re-assessing the state of dial-out routeservices of the first gateway to restore the retrieved dial-out route ina routing table in the first gateway.
 38. A computer program productcomprising: a computer usable medium for storing data; and a set ofcomputer program instructions embodied on the computer usable medium,including instructions to: determine a dial-out route is available by asecond gateway; transfer a dial-out route from a first gateway to thesecond gateway in a data communications network; cause a routing tablein the second gateway to include the dial-out route; and effectuatedial-out services of the dial-out route via a routing protocol by thesecond gateway to reduce congestion for nodes in the data communicationsnetwork.
 39. The computer program product according to claim 38 whereinthe set of computer program instructions further includes instructionsto terminate dial-out route services of the transferred dial-out routeby the second gateway.
 40. The computer program product according toclaim 38 wherein the set of computer program instructions furtherinclude instructions to transfer a priority level parameter associatedwith the dial-out route.
 41. The computer program product according toclaim 38 wherein the set of computer program instructions furtherinclude (i) instructions to advertise dial -out services of the dial-outroute to the network via a routing protocol prior to transferring thedial-out route and (ii) instructions to disable advertising dial-outservices of the dial-out route following transfer of the dial-out route.42. A method for scaling dial-out services provided by a gateway in adata communications network to reduce congestion in the datacommunications network, the method comprising: by a second gateway,receiving from a first gateway dial-out route information correspondingto at least one dial-out route; updating a routing table in the secondgateway with the dial-out route information; and by the second gateway,advertising the dial-out services for the at least one dial-out route tonetwork nodes that access the second gateway to effectuate transfer ofdial-out services of the at least one dial-out route.
 43. The methodaccording to claim 42 further including accessing a central databasestoring static routes corresponding to the transferred dial-out routeinformation.
 44. The method according to claim 43 wherein the centraldatabase is stored on a server providing security services.
 45. Themethod according to claim 42, further including: responding to a requestfrom the first gateway to transfer the at least one dial-out routecorresponding to the dial-out route information prior to receiving thedial-out route.
 46. The method according to claim 45, further includingchoosing whether to accept the at least one dial-out route.
 47. Themethod according to claim 42, wherein receiving the dial-out routeinformation includes receiving a respective priority level parameterassociated with the at least one dial-out route.
 48. The methodaccording to claim 47 further including advertising the transferred atleast one dial-out route and respective priority levels by the secondgateway to effectuate dial-out service using the at least one dial-outroute by the network nodes.
 49. The method according to claim 42 whereinreceiving the dial-out route information further includes receiving atleast one transfer termination parameter to limit the length of timedial-out services of the at least one dial-out route is available to thenetwork nodes by the second gateway.
 50. The method according to claim49 wherein the at least one transfer termination parameter includes atleast one of the following parameters: time-to-live, delete-after-complete, or delete-upon-reboot.
 51. A system for scalingdial-out services provided by a gateway in a data communications networkto reduce congestion in the data communications network, the systemcomprising: a second gateway advertising dial-out services for at leastone dial-out route to the data communications network via a routingprotocol; a routing table in a second gateway including at least onedial-out route, the second gateway receiving from a first gateway atleast one parameter related to a static dial-out route for adding to therouting table, the second gateway advertising the dial-out servicescorresponding to the static dial-out route associated with the at leastone transferred parameter to reduce congestion in the datacommunications network.
 52. The system according to claim 51 wherein thesecond gateway accesses a server providing a reachability database, thereachability database including static routes accessible by the firstand second gateways.
 53. The system according to claim 52 wherein thefirst gateway is adapted to access the server via security servicesemployed by the server.
 54. The system according to claim 53 wherein theserver is an access, authentication, and authorization server.
 55. Thesystem according to claim 52 wherein the second gateway retrievesdial-out routes from the reachability database.
 56. The system accordingto claim 51 wherein the second gateway receives the static routeparameters in response to the first gateway determining a reduced numberof gateway ports being able to provide dial-out route services for astatic route corresponding to the at least one static route parameters.57. The system according to claim 51 wherein the second gatewayadvertises transferred dial-out routes on the data communicationsnetwork as a function of capacity resulting from receiving the dial-outservices for the respective static route.
 58. The system according toclaim 52 wherein the second gateway receives a dial -out route priorityparameter in the at least one transferred parameter and includes thedial-out route priority parameter in advertisements about the staticroute dial -out service to other network nodes.
 59. The system accordingto claim 58 wherein the second gateway calculates the static routepriority parameter.
 60. The system according to claim 58 wherein thesecond gateway receives information from the first gateway andcalculates the static route priority parameter based on the receivedinformation.
 61. The system according to claim 51 wherein a serverincluding a reachability database accessible by the first and secondgateways includes the static route priority parameter in the database.62. The system according to claim 51 wherein the second gatewayterminates dial -out service of the transferred static route by thesecond gateway.
 63. The system according to claim 30 wherein the secondgateway receives a termination parameter from the first gateway, thetermination parameter causing the second gateway to terminate thetransferred static route.
 64. An apparatus for scaling dial-out servicesprovided by a gateway in a data communications network to reducecongestion in the data communications network, the apparatus comprising:means for receiving dial-out routes from a first gateway to a secondgateway; means for increasing priority of the transferred dial-out routein the second gateway above the priority of the transferred dial-outroute in the first gateway; means for updating a routing table in thesecond gateway; and means for advertising the dial-out route via arouting protocol to the data communications network as a function of thepriority level of the at least one dial-out route.
 65. The apparatusaccording to claim 64 wherein said means for advertising the dial-outroute informs reachable network nodes of respective gateway routes andcorresponding gateway route priorities to reduce data flow congestion inthe data communications network.
 66. The apparatus according to claim 64wherein said means for updating a routing table enables the dial-outroute to be accessed via the second gateway by network nodes in the datacommunications network.
 67. The apparatus according to claim 64 whereinsaid means for receiving the dial -out route includes means forreceiving a terminating parameter that causes the transferred dial-outroute to terminate in the second gateway according to a predeterminedcondition.
 68. A method for dynamically providing dial-out service for anetwork node by a gateway, the method comprising: determining a state ofdial-out services in a second gateway; retrieving at least one dial-outroute reachable from the first gateway from a central database storingdial-out routes for the first gateway; updating a routing table in thesecond gateway with the retrieved dial-out route to provide dial-outservices to the dial-out route; and advertising the dial-out route via arouting protocol by the second gateway to cause network nodes to accessthe second gateway for dial-out services of the dial-out route.
 69. Themethod according to claim 68 further including removing the dial-outroute from the routing table in the second gateway to discontinueproviding dial-out services for the retrieved dial-out route.
 70. Acomputer program product comprising: a computer usable medium forstoring data; and a set of computer program instructions embodied on thecomputer usable medium, including instructions to: determine a dial-outroute is available to a second gateway; receive a dial-out route from afirst gateway to the second gateway in a data communications network;cause a routing table in the second gateway to include the dial-outroute; and effectuate dial-out services of the dial-out route via arouting protocol by the second gateway to reduce congestion for nodes inthe data communications network.
 71. The computer program productaccording to claim 70 wherein the set of computer program instructionsfurther includes instructions to terminate dial-out route services ofthe transferred dial-out route by the second gateway.
 72. The computerprogram product according to claim 70 wherein the set of computerprogram instructions further include instructions to receive a prioritylevel parameter associated with the dial-out route.
 73. The computerprogram product according to claim 70 wherein the set of computerprogram instructions further include (i) instructions to advertise dial-out services of the dial-out route to the network via a routingprotocol following receipt of the dial-out route and (ii) instructionsto disable advertising dial-out services of the dial-out route followinga transfer of the dial-out route back to the first gateway.